[Koha] I need help with Koha OAI Server

[benson Mugambi]

Hi folks,I am working on availing koha database for external indexing using OAI:PMH but i have run into some difficulties. 
I believe members of this community with experience working on OAI can give clues on how to resolve.
First i am running Koha-common 3.18.05.100 on ubuntu trusty 14.04 - 64bit 
All the perl modules are in green status apart from Readonly::XS which i have fiddled with unsuccessfully.
I am able to index and search all records without any problems . I have enabled OAI server and configured sets from the intranet interface but i have ran into difficulties immediately when trying to build the sets:
Earlier on i was unable to find the standard OAI command among the commands provided by debian packages (http://wiki.koha-community.org/wiki/Commands_provided_by_the_Debian_packages). 
When i tried to do it directly i got an exception:
root at bibliotheque:~# /usr/share/koha/bin/migration_tools/build_oai_sets.pl -o -l -v
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
unable to locate Koha configuration file koha-conf.xml at /usr/share/koha/lib/C4/Context.pm line 373.
Can't call method "config" on unblessed reference at /usr/share/koha/lib/C4/Context.pm line 779.

Eventually, i was able to execute the build sets by issuing the command 
sudo KOHA_CONF=/etc/koha/sites/library/koha-conf.xml PERL5LIB=/usr/share/koha/lib /usr/share/koha/bin/migration_tools/build_oai_sets.pl -o -l -v
I thought i was out of the woods, but accessing the OAI url produced another exception:
 
XML Parsing Error: junk after document element
Location: http://localhost:8001/cgi-bin/koha/oai.pl
Line Number 2, Column 1:<pre>Can't call method "start_element" on an undefined value at /usr/local/share/perl/5.18.2/HTTP/OAI/Response.pm line 114.
^

How do i move forward from here? I have almost reached the EOTC (End of Thinking Capacity)
Regards,
Benson